return to home page

IV.D.1. (XII.C.1.)

Geometry Comparison

C4H4N2 (1,3-Diazine)


distance is atom 2 (C) to atom 6 (N)

Experimental bond length is 1.328  Å

Display Options
Switch to bar chart display
Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.357
PM6 1.376
composite G2 1.319
G3 1.319
G3B3 1.338
G4 1.333

Calculated bond length in Å
Methods with standard basis sets
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 1.354 1.329 1.329 1.330 1.318 1.319 1.319 1.317 1.318 1.316 1.315 1.316 1.320 1.315 1.321 1.315
density functional LSDA 1.386 1.344 1.344 1.345 1.332 1.332 1.333 1.328 1.328 1.328     1.333 1.326 1.333  
SVWN   1.342     1.332   1.334                  
BLYP 1.413 1.365   1.365 1.351 1.351 1.352   1.348 1.348     1.353 1.345 1.352  
B1B95 1.383 1.345 1.345 1.345 1.330 1.332 1.332 1.329 1.329 1.329     1.333 1.325 1.331  
B3LYP 1.392 1.350 1.350 1.351 1.338 1.338 1.339 1.335   1.334 1.332 1.334 1.339 1.332    
B3LYPultrafine         1.338   1.339             1.333   1.331
B3PW91   1.348 1.348 1.348 1.335 1.335   1.332   1.332     1.336 1.330 1.336  
mPW1PW91   1.345   1.346 1.332 1.332 1.333 1.329 1.330 1.329     1.334   1.333  
M06-2X         1.333                      
PBEPBE   1.361     1.346 1.346 1.347 1.343 1.343 1.343 1.340   1.347 1.341    
PBEPBEultrafine         1.345                      
PBE1PBE         1.332                      
HSEh1PBE         1.333                      
TPSSh         1.339   1.339             1.333    
Moller Plesset perturbation MP2   1.366 1.366 1.369 1.342 1.342 1.343 1.341 1.341 1.338   1.338 1.347 1.337    
MP2=FULL         1.341     1.340                
MP3         1.337   1.337                  
MP3=FULL         1.336   1.337                  
B2PLYP         1.339                 1.334    
B2PLYP=FULLultrafine         1.339                      
Quadratic configuration interaction QCISD                 1.339              

Calculated bond length in Å
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 1.344 1.330 1.342 1.326 1.336 1.336
density functional B1B95 1.361 1.345        
B3LYP 1.369 1.351 1.365 1.346 1.357 1.358
Moller Plesset perturbation MP2 1.391 1.357 1.383 1.352 1.379 1.379
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
Please use the error report form to report problems.